float SVGLengthContext::convertValueToUserUnits(float value, SVGLengthMode mode, CSSPrimitiveValue::UnitType fromUnit) const
{
float userUnits = value;
switch (fromUnit) {
case CSSPrimitiveValue::UnitType::Pixels:
case CSSPrimitiveValue::UnitType::Number:
case CSSPrimitiveValue::UnitType::UserUnits:
userUnits = value;
break;
case CSSPrimitiveValue::UnitType::Percentage: {
FloatSize viewportSize;
if (!determineViewport(viewportSize))
return 0;
userUnits = value * dimensionForLengthMode(mode, viewportSize) / 100;
break;
}
case CSSPrimitiveValue::UnitType::Ems:
userUnits = convertValueFromEMSToUserUnits(computedStyleForLengthResolving(m_context), value);
break;
case CSSPrimitiveValue::UnitType::Exs:
userUnits = convertValueFromEXSToUserUnits(value);
break;
case CSSPrimitiveValue::UnitType::Centimeters:
userUnits = value * cssPixelsPerCentimeter;
break;
case CSSPrimitiveValue::UnitType::Millimeters:
userUnits = value * cssPixelsPerMillimeter;
break;
case CSSPrimitiveValue::UnitType::Inches:
userUnits = value * cssPixelsPerInch;
break;
case CSSPrimitiveValue::UnitType::Points:
userUnits = value * cssPixelsPerPoint;
break;
case CSSPrimitiveValue::UnitType::Picas:
userUnits = value * cssPixelsPerPica;
break;
case CSSPrimitiveValue::UnitType::Rems:
userUnits = convertValueFromEMSToUserUnits(rootElementStyle(m_context), value);
break;
case CSSPrimitiveValue::UnitType::Chs:
userUnits = convertValueFromCHSToUserUnits(value);
break;
case CSSPrimitiveValue::UnitType::ViewportWidth:
case CSSPrimitiveValue::UnitType::ViewportHeight:
case CSSPrimitiveValue::UnitType::ViewportMin:
case CSSPrimitiveValue::UnitType::ViewportMax:
userUnits = value * dimensionForViewportUnit(m_context, fromUnit);
break;
default:
ASSERT_NOT_REACHED();
break;
}
// Since we mix css <length> values with svg's length values we need to
// clamp values to the narrowest range, otherwise it can result in
// rendering issues.
return CSSPrimitiveValue::clampToCSSLengthRange(userUnits);
}
float SVGLengthContext::convertValueFromUserUnits(
float value,
SVGLengthMode mode,
CSSPrimitiveValue::UnitType toUnit) const {
switch (toUnit) {
case CSSPrimitiveValue::UnitType::Pixels:
case CSSPrimitiveValue::UnitType::Number:
case CSSPrimitiveValue::UnitType::Integer:
case CSSPrimitiveValue::UnitType::UserUnits:
return value;
case CSSPrimitiveValue::UnitType::Percentage: {
FloatSize viewportSize;
if (!determineViewport(viewportSize))
return 0;
float dimension = dimensionForLengthMode(mode, viewportSize);
if (!dimension)
return 0;
// LengthTypePercentage is represented with 100% = 100.0.
// Good for accuracy but could eventually be changed.
return value * 100 / dimension;
}
case CSSPrimitiveValue::UnitType::Ems:
return convertValueFromUserUnitsToEMS(
computedStyleForLengthResolving(m_context), value);
case CSSPrimitiveValue::UnitType::Exs:
return convertValueFromUserUnitsToEXS(value);
case CSSPrimitiveValue::UnitType::Rems:
return convertValueFromUserUnitsToEMS(rootElementStyle(m_context), value);
case CSSPrimitiveValue::UnitType::Chs:
return convertValueFromUserUnitsToCHS(value);
case CSSPrimitiveValue::UnitType::Centimeters:
return value / cssPixelsPerCentimeter;
case CSSPrimitiveValue::UnitType::Millimeters:
return value / cssPixelsPerMillimeter;
case CSSPrimitiveValue::UnitType::Inches:
return value / cssPixelsPerInch;
case CSSPrimitiveValue::UnitType::Points:
return value / cssPixelsPerPoint;
case CSSPrimitiveValue::UnitType::Picas:
return value / cssPixelsPerPica;
case CSSPrimitiveValue::UnitType::ViewportWidth:
case CSSPrimitiveValue::UnitType::ViewportHeight:
case CSSPrimitiveValue::UnitType::ViewportMin:
case CSSPrimitiveValue::UnitType::ViewportMax:
return value / dimensionForViewportUnit(m_context, toUnit);
default:
break;
}
ASSERT_NOT_REACHED();
return 0;
}